CN110571843A - Method for evaluating influence of power grid fluctuation on load of wind turbine generator - Google Patents
Method for evaluating influence of power grid fluctuation on load of wind turbine generator Download PDFInfo
- Publication number
- CN110571843A CN110571843A CN201910669289.9A CN201910669289A CN110571843A CN 110571843 A CN110571843 A CN 110571843A CN 201910669289 A CN201910669289 A CN 201910669289A CN 110571843 A CN110571843 A CN 110571843A
- Authority
- CN
- China
- Prior art keywords
- generator
- power grid
- wind turbine
- load
- grid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Eletrric Generators (AREA)
Abstract
The invention relates to a method for evaluating the influence of power grid fluctuation on the load of a wind turbine generator, which comprises the steps of building an electric model of a power grid, a converter and a wind double-fed generator, and a wind turbine generator mechanical model comprising load transmission, so as to finally obtain the output torque of the generator influenced by the power grid fluctuation, and determining the load condition of the wind turbine generator mechanical model under the output torque of the generator influenced by the power grid fluctuation; and comparing the obtained load condition with the load condition of the mechanical model of the wind turbine generator under the normal operation condition of the power grid, and evaluating the influence of the power grid fluctuation on the load of the wind turbine generator. According to the method, the load state under various power grid fluctuation running conditions is simulated by building the power grid, the electric model of the converter connected with the wind double-fed generator and the wind turbine generator mechanical model containing load transmission, so that the influence of power grid fluctuation on the wind turbine generator load is determined, the method is simple and easy to operate, and the obtained result is high in reliability and accuracy.
Description
Technical Field
The invention belongs to the technical field of wind power generation, and particularly relates to a method for evaluating the influence of power grid fluctuation on load of a wind turbine generator.
Background
The wind generating set converts wind energy into rotating mechanical energy by utilizing a blade momentum theory of an impeller, and converts the mechanical energy into electric energy by utilizing devices such as a generator, a converter and the like. Under an ideal condition, three-phase voltage, current and frequency of a power grid stably operate, but at present, a plurality of wind power plants are in a power grid access area which is sparsely populated and far away from a load center, the power grid is relatively weak, voltage, current or frequency fluctuation of the power grid caused by cut-out, short circuit, faults and the like of a heavy load is easy to occur, and the electromagnetic torque of a generator can be changed and fan parts can be damaged under an extreme condition due to the fact that a sudden power grid fluctuation converter cannot respond to the current and the current.
Most of wind generating sets in the current market are permanent magnet synchronous and double-fed asynchronous. The permanent magnet synchronous generator is connected with a power grid through the converter, and when the power grid fluctuates, damage to the wind turbine generator can be reduced through the regulation of the converter properly. And double-fed generating set adopts wound-rotor asynchronous machine, the stator side directly links to each other with the electric wire netting, the rotor side links to each other with the electric wire netting through back-to-back converter, the sudden change of electric wire netting voltage can cause great impulse current at the stator side, and the electromagnetic coupling between stator and rotor also can lead to rotor side current fluctuation, arouses that the motor electromagnetic torque is undulant, wind turbine generator system electromagnetic torque frequently mismatches with mechanical torque, can lead to the drive chain load to rise, it is great to gear box internal tooth class and axle class spare part damage. Therefore, how to accurately evaluate the influence of sudden grid voltage change, three-phase imbalance or frequency fluctuation on the electromagnetic torque of the wind turbine generator, and provide reasonable parameters for a fan control strategy, and the method has a remarkable significance on the safe and stable operation of the wind turbine generator.
In recent years, researches are carried out by various complete machine manufacturers and scholars at home and abroad about the influence problem of power grid faults on the wind turbine generator, for example, the Chinese patent with application publication number CN102819221A discloses a combined simulation model of low voltage ride through characteristics of the wind turbine generator and a simulation method thereof, the method communicates a blanked mechanical model and an MATLAB electrical model through a socket communication interface to simulate the load condition of a transmission chain of the wind turbine generator under different low voltage ride through conditions, and because a blanked hardware test module cannot simulate the high-order modal deformation condition, the method needs to limit the modal frequency of main components of the wind turbine generator, such as blades and a tower, and can only simulate the load condition under low frequency in the simulation process.
Disclosure of Invention
The invention provides a method for evaluating the influence of power grid fluctuation on the load of a wind turbine generator, which is used for solving the problem that the prior art can only simulate the load condition under low frequency.
in order to solve the technical problems, the technical scheme and the beneficial effects of the invention are as follows:
The invention discloses a method for evaluating the influence of power grid fluctuation on load of a wind turbine generator, which comprises the following steps of:
1) Establishing an electric model for connecting a power grid, a converter and a wind power double-fed generator, and changing the output power of the generator under the normal operation condition of the power grid and the fluctuation operation condition of the power grid respectively to obtain the electromagnetic torque of the generator corresponding to the output power grade of each generator under different power grid operation conditions;
2) Under the same output power level of the generator, the ratio of the electromagnetic torque of the generator under the condition of power grid fluctuation operation to the electromagnetic torque of the generator under the condition of power grid normal operation is obtained, and the ratio corresponding to the output power level of each generator is obtained;
3) Building a mechanical model of the wind turbine generator, which comprises load transmission, and changing the air density and/or the wind speed to obtain generator torque corresponding to the output power grade of each generator;
4) Under the same output power level of the generator, multiplying the generator torque obtained in the step 3) by the ratio obtained in the step 2) to obtain a generator output torque influenced by grid fluctuation, and determining the load condition of a mechanical model of the wind turbine generator under the generator output torque influenced by the grid fluctuation;
5) Comparing the load condition obtained in the step 4) with the load condition of the mechanical model of the wind turbine generator without considering the power grid fluctuation, and evaluating the influence of the power grid fluctuation on the load of the wind turbine generator.
the beneficial effects are as follows: according to the method, load states under various power grid fluctuation running conditions are simulated by building an electric model of a power grid, a converter and a wind power double-fed generator, and a wind turbine generator mechanical model containing load transmission, so that the influence of power grid fluctuation on the wind turbine generator load is determined.
Further, in order to simulate different grid fluctuation operation conditions to evaluate the influence of different grid fluctuations on the load of the wind turbine generator, the grid fluctuation operation conditions include: grid voltage rise, grid voltage drop, and grid three-phase imbalance.
drawings
FIG. 1 is a simplified process flow diagram of the present invention;
Fig. 2 is a flow chart of the method of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.
The method comprises the following steps:
because the rotational inertia of the wind wheel is large, the influence of sudden change of the power grid on the mechanical torque of the transmission chain is small, and the component with large influence on the shafting is reflected on the electromagnetic torque of the motor, the embodiment provides a method for evaluating the influence of power grid fluctuation on the load of the wind turbine generator, and the method is described in detail by combining fig. 1 and 2.
Firstly, establishing a power grid, a converter and a wind power double-fed generator (hereinafter referred to as a generator) in an MATLAB/Simulink simulation platform to be connectedThe electrical model of (1). By setting different input signals set0, set1, set2 and set3, the normal operation condition and the power grid fluctuation operation condition (including three conditions of power grid voltage increase, power grid voltage decrease and three-phase imbalance) of the power grid are simulated, and different generator output powers P are set at a converteriAnd collecting electromagnetic torque signals of the generators to obtain electromagnetic torque curves corresponding to the output power levels of the generators under different power grid operation conditions.
Wherein, under the condition of normal operation of the power grid, the output power grade (P) of each generator1、P2、…、Pk) The following electromagnetic torque curves of the generator are respectively: t is10(t)、T20(t)、…、Tk0(t)；
the output power grade (P) of each generator is increased under the condition of grid voltage1、P2、…、Pk) The following electromagnetic torque curves of the generator are respectively: t is11(t)、T21(t)、…、Tk1(t)；
Output power class (P) of each generator in case of grid voltage reduction1、P2、…、Pk) The following electromagnetic torque curves of the generator are respectively: t is12(t)、T22(t)、…、Tk2(t)；
Under the condition of three-phase unbalance of the power grid, different generator output power levels (P)1、P2、…、Pk) The following electromagnetic torque curves of the generator are respectively: t is13(t)、T23(t)、…、Tk3(t)。
then, the electromagnetic torque curve T of the generator under the condition of fluctuating operation of each power grid obtained in the previous step is usedi1(t)、Ti2(t)、Ti3(T) Generator electromagnetic Torque curves T respectively associated with the grid under Normal operation conditionsi0(t) plotting the ratio to obtain ηi1(t)、ηi2(t)、ηi3(t); wherein, i is 1, 2, …, k.
under the condition that the voltage of the power grid is increased, the time domain function of the corresponding ratio curve is as follows:
In the formula etai1(t) denotes the rise of the grid voltage PiRatio curve of generator electromagnetic torque, T, at power leveli1indicating a rise in grid voltage PiExcitation torque curve, T, of generator under power leveli0Indicating normal operation of the grid voltageiand generating an electromagnetic torque curve of the generator at the power level.
Under the condition that the voltage of the power grid is reduced, the time domain function of the corresponding ratio curve is as follows:
in the formula etai2(t) represents the grid voltage drop PiRatio curve of generator electromagnetic torque, T, at power leveli2Indicating a reduction in grid voltage PiExcitation torque curve, T, of generator under power leveli0Indicating normal operation of the grid voltageiAnd generating an electromagnetic torque curve of the generator at the power level.
Under the condition of three-phase imbalance of the power grid, the time domain function of the corresponding ratio curve is as follows:
In the formula etai3(t) represents P when three phases of the power grid are unbalancediRatio curve of generator electromagnetic torque, T, at power leveli3When representing three-phase unbalance of power gridiExcitation torque curve, T, of generator under power leveli0Indicating normal operation of the grid voltageiAnd generating an electromagnetic torque curve of the generator at the power level.
Then, mechanical models of the wind turbine generator with load transmission are respectively built in a blanked simulation platform to simulate the torque power curve of the generator under the condition of low turbulence at different wind speeds, (P)ref1、Pref2、…、Prefi)，By using the principle that the torque and the power with similar rotating speeds are positively correlated, the electromagnetic torque curve T of the generator1(t)、T2(t)、…、Ti(t) is:
In the formula, ni(T) is a generator speed curve under a certain wind speed, when the wind speed turbulence is low and the control precision is high, the fluctuation of the generator speed is very small, and the curve T can be usedi(t) as the unit power Prefi(t) representative curve of electromagnetic torque by plotting the power curve P in the Bladed simulationrefi(t) Power Curve (P) in MATLAB/Simulink simulation1、P2、…、Pi) Match is made if Prefi(t) and Piclose, then curve Ti(t) may also be the power level Piand (4) generating a torque curve of the generator.
Thirdly, a ratio curve eta simulated by MATLAB/Simulinki1(t)、ηi2(t)、ηi3(T) Generator Torque curves T simulated with the corresponding Bladed, respectively1(t)、T2(t)、…、Ti(T) multiplication to generate a grid fluctuation-affected generator output torque curve T for evaluation of load simulation analysisi1′(t)、Ti2′(t)、Ti3′(t)。
Under the condition that the voltage of the power grid is increased, the time domain function and the frequency domain function of the corresponding power generator output torque curve affected by the fluctuation of the power grid are respectively as follows:
Ti1′(t)＝T1(t)*ηi1(t)
In the formula, Ti1' (t) denotes the rise of the mains voltage Pitime-domain function, X, of the grid-ripple-affected generator output torque curve at power leveli1(omega) denotes the rise of the grid voltage PiFrequency domain function of the grid fluctuation-affected generator output torque curve at power level, e-jwtRepresenting a complex function over a range of frequencies.
Under the condition that the voltage of the power grid is reduced, the time domain function and the frequency domain function of the corresponding power generator output torque curve affected by the fluctuation of the power grid are respectively as follows:
Ti2′(t)＝T2(t)*ηi2(t)
In the formula, Ti2' (t) denotes P when the grid voltage decreasesiTime-domain function, X, of the grid-ripple-affected generator output torque curve at power leveli2(omega) represents the grid voltage reduction PiFrequency domain function of the grid fluctuation-affected generator output torque curve at power level, e-jwtRepresenting a complex function over a range of frequencies.
Under the unbalanced three-phase condition of the power grid, the time domain function and the frequency domain function of the corresponding power generator output torque curve affected by the power grid fluctuation are respectively as follows:
Ti3′(t)＝T3(t)*ηi3(t)
In the formula, Ti3' (t) denotes P when three phases of the grid are unbalancediTime-domain function, X, of the grid-ripple-affected generator output torque curve at power leveli2(omega) represents P when three phases of the power grid are unbalancediFrequency domain function of the grid fluctuation-affected generator output torque curve at power level, e-jwtRepresenting a complex function over a range of frequencies.
finally, the generator output torque curve T will be affected by grid fluctuationsi1′(t)、Ti2′(t)、Ti3' (t) introducing the simulation result into a mechanical model of the wind turbine set built in a blanked simulation platform for load calculation, and simulating different power gridsUnder the condition of fluctuation operation, the load impact condition of the wind turbine generator is obtained, namely the load condition of a mechanical model of the wind turbine generator under the output torque of the generator influenced by power grid fluctuation is obtained; and comparing the load condition of the mechanical model of the wind turbine generator under the condition of the output torque of the generator influenced by the power grid fluctuation with the load condition of the mechanical model of the wind turbine generator under the condition of not considering the power grid fluctuation so as to evaluate the influence of the power grid fluctuation on the load of the wind turbine generator.
In addition, in obtaining the frequency domain function X of the generator output torque curve affected by the grid fluctuationi1(ω)、Xi2(ω)、Xi3After the (omega), the three functions can be analyzed to obtain corresponding amplitude and frequency, the influence and change of the power grid fluctuation on the electromagnetic torque fluctuation amplitude and frequency of the generator are determined, direct reference is provided for modifying a transmission chain damping function and a torque control PI parameter in a control strategy, and therefore the purpose of further optimizing the running load of the wind turbine generator is achieved.
On the whole, the method is comprehensive in consideration and simple and easy to operate by building an electric model for connecting a power grid, a converter and a wind power double-fed generator and simulating to obtain a ratio curve under three power grid fluctuation conditions of power grid voltage increase, power grid voltage decrease and power grid three-phase imbalance; moreover, curves with different ratios are superposed in a blanked simulation platform to simulate the load impact of different power grid fluctuation running conditions on the wind turbine generator, so that the simulation result is more accurate and reliable.
While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.
Claims (2)
1. A method for evaluating the influence of power grid fluctuation on the load of a wind turbine generator is characterized by comprising the following steps:
1) Establishing an electric model for connecting a power grid, a converter and a wind power double-fed generator, and changing the output power of the generator under the normal operation condition of the power grid and the fluctuation operation condition of the power grid respectively to obtain the electromagnetic torque of the generator corresponding to the output power grade of each generator under different power grid operation conditions;
2) Under the same output power level of the generator, the ratio of the electromagnetic torque of the generator under the condition of power grid fluctuation operation to the electromagnetic torque of the generator under the condition of power grid normal operation is obtained, and the ratio corresponding to the output power level of each generator is obtained;
3) building a mechanical model of the wind turbine generator, which comprises load transmission, and changing the air density and/or the wind speed to obtain generator torque corresponding to the output power grade of each generator;
4) Under the same output power level of the generator, multiplying the generator torque obtained in the step 3) by the ratio obtained in the step 2) to obtain a generator output torque influenced by grid fluctuation, and determining the load condition of a mechanical model of the wind turbine generator under the generator output torque influenced by the grid fluctuation;
5) Comparing the load condition obtained in the step 4) with the load condition of the mechanical model of the wind turbine generator without considering the power grid fluctuation, and evaluating the influence of the power grid fluctuation on the load of the wind turbine generator.
2. The method for evaluating the influence of grid fluctuations on the load of a wind turbine generator as claimed in claim 1, wherein the grid fluctuation operating conditions comprise: grid voltage rise, grid voltage drop, and grid three-phase imbalance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910669289.9A CN110571843B (en) | 2019-07-23 | 2019-07-23 | Method for evaluating influence of power grid fluctuation on load of wind turbine generator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910669289.9A CN110571843B (en) | 2019-07-23 | 2019-07-23 | Method for evaluating influence of power grid fluctuation on load of wind turbine generator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110571843A true CN110571843A (en) | 2019-12-13 |
| CN110571843B CN110571843B (en) | 2021-11-19 |
Family
ID=68773514
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910669289.9A Active CN110571843B (en) | 2019-07-23 | 2019-07-23 | Method for evaluating influence of power grid fluctuation on load of wind turbine generator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110571843B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111478321A (en) * | 2020-04-23 | 2020-07-31 | 许昌许继风电科技有限公司 | Power distribution network node selection method for connecting distributed wind power generation system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101750216A (en) * | 2010-01-28 | 2010-06-23 | 清华大学 | Online analysis method for turbonator shafting fatigue damage caused by subsynchronous oscillation |
| CN106907295A (en) * | 2015-12-22 | 2017-06-30 | 通用电气公司 | Wind generator system and its control method |
| CN108204336A (en) * | 2018-01-30 | 2018-06-26 | 北京金风科创风电设备有限公司 | Wind generating set stopping method and device, storage medium and computing device |
| CN109995052A (en) * | 2017-12-29 | 2019-07-09 | 北京金风科创风电设备有限公司 | Subsynchronous suppression method and device and controller of converter |
-
2019
- 2019-07-23 CN CN201910669289.9A patent/CN110571843B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101750216A (en) * | 2010-01-28 | 2010-06-23 | 清华大学 | Online analysis method for turbonator shafting fatigue damage caused by subsynchronous oscillation |
| CN106907295A (en) * | 2015-12-22 | 2017-06-30 | 通用电气公司 | Wind generator system and its control method |
| CN109995052A (en) * | 2017-12-29 | 2019-07-09 | 北京金风科创风电设备有限公司 | Subsynchronous suppression method and device and controller of converter |
| CN108204336A (en) * | 2018-01-30 | 2018-06-26 | 北京金风科创风电设备有限公司 | Wind generating set stopping method and device, storage medium and computing device |
Non-Patent Citations (2)
| Title |
|---|
| 时培明等: "激光测量大型转轴动载波动系数原理", 《机械工程学报》 * |
| 苗风麟等: "风力发电机组多领域耦合模型及动态响应分析", 《中国电机工程学报》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111478321A (en) * | 2020-04-23 | 2020-07-31 | 许昌许继风电科技有限公司 | Power distribution network node selection method for connecting distributed wind power generation system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110571843B (en) | 2021-11-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Trudnowski et al. | Fixed-speed wind-generator and wind-park modeling for transient stability studies | |
| Ellis et al. | Description and technical specifications for generic WTG models—A status report | |
| Muljadi et al. | Effect of variable speed wind turbine generator on stability of a weak grid | |
| Sun et al. | Flicker study on variable speed wind turbines with doubly fed induction generators | |
| Qiao et al. | Dynamic modeling of wind farms with fixed-speed wind turbine generators | |
| Cidras et al. | A linear dynamic model for asynchronous wind turbines with mechanical fluctuations | |
| CN109217362A (en) | A kind of double-fed blower grid-connected system low-frequency oscillation disturbance source locating system and method | |
| Thomsen et al. | Technological advances in hydraulic drive trains for wind turbines | |
| CN105591402B (en) | A kind of modeling and simulation method and apparatus of direct-drive permanent-magnetism Wind turbines | |
| CN104329220A (en) | Torsion load controller for restraining torsional vibration of wind turbine generator and control method | |
| CN101685139A (en) | Simulation test system of large directly driven permanent magnet wind generating set | |
| CN105221353A (en) | Method for diagnosing impeller pneumatic asymmetric fault of double-fed wind generating set | |
| Vilar et al. | A frequency domain approach to wind turbines for flicker analysis | |
| CN104675629A (en) | Maximum wind energy capturing method of variable-speed wind generating sets | |
| CN102156044B (en) | Model selection method of wind turbine simulator applicable to testing of direct driving type wind generating set | |
| CN103076745A (en) | Simulation method for wind turbine generator model in conventional power system simulation software | |
| Weijie et al. | Investigating instability of the wind turbine simulator with the conventional inertia emulation scheme | |
| CN105762816A (en) | Method for inhibiting subsynchronous interaction | |
| Mohammadi et al. | An electromechanical emulation-based study on the behaviour of wind energy conversion systems during short circuit faults | |
| CN110571843B (en) | Method for evaluating influence of power grid fluctuation on load of wind turbine generator | |
| Nye et al. | Design and implementation of a variable speed wind turbine emulator | |
| CN104200027B (en) | A kind of wind power plant equivalent modeling method and device for considering low voltage crossing characteristic | |
| Fadaeinedjad et al. | A new wind power plant simulation method to study power quality | |
| Li et al. | A study on dynamic model and analyse of wind turbine generation system | |
| Bekker | Efficient modelling of a wind turbine system for parameter estimation applications |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| TA01 | Transfer of patent application right | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20210508 Address after: 461000 Zhongyuan Electric valley wind power industrial park, Weiwu Avenue, Xuchang City, Henan Province Applicant after: XUCHANG XUJI WIND POWER TECHNOLOGY Co.,Ltd. Applicant after: STATE GRID JIBEI ELECTRIC POWER Co.,Ltd. Address before: 461000 Xuji Wind Power Industrial Park, Zhongyuan Electric Valley, Weiwu Avenue, Dongcheng District, Xuchang City, Henan Province Applicant before: XUCHANG XUJI WIND POWER TECHNOLOGY Co.,Ltd. |
|
| GR01 | Patent grant | ||
| GR01 | Patent grant |